mardi 27 novembre 2012

OBJECTIVE:
The aim of this study was to assess the prognostic and predictive values of
circulating tumor cell (CTC) analysis in colorectal cancer patients.Patients
and methodsPresence of CTCs was evaluated in 60 colorectal cancer patients
before systemic therapy - from which 33 patients were also evaluable for CTC
analysis during the first 3 months of treatment - through immunomagnetic
enrichment, using the antibodies BM7 and VU1D9 (targeting mucin 1 and EpCAM,
respectively), followed by real-time RT-PCR analysis of the tumor-associated
genes KRT19, MUC1, EPCAM, CEACAM5 and BIRC5.

RESULTS:

Patients
were stratified into groups according to CTC detection (CTC negative, when all
marker genes were negative; and CTC positive when at least one of the marker
genes was positive). Patients with CTC positivity at baseline had a significant
shorter median progression-free survival (median PFS 181.0 days; 95% CI
146.9-215.1) compared with patients with no CTCs (median PFS 329.0 days; 95% CI
299.6-358.4; Log-rank P < .0001). Moreover, a statistically significant
correlation was also founded between CTC detection during treatment and
radiographic findings at the 6 month staging. This correlation applied to CTC
results before therapy (odds ratio (OR), 6.22), 1 to 4 weeks after beginning of
treatment (OR, 5.50), 5 to 8 weeks after beginning of treatment (OR, 7.94) 9 to
12 weeks after beginning of treatment (OR, 14.00) and overall CTC fluctuation
during the course of treatment (OR, 20.57).

CONCLUSION:

The
present study provides evidence of a strong correlation between CTC detection
and radiographic disease progression in patients receiving chemotherapy for
colorectal cancer. Our results suggest that in addition to the current
prognostic factors, CTC analysis represent a potential complementary tool for
prediction of colorectal cancer patients' outcome. Moreover, the present test
allows for molecular characterization of CTCs, which may be of relevance to the
creation of personalized therapies.